It is known from U.S. Pat. No. 3,817,910 to Viksne, that compression set of heat curable silicone rubber can be improved by incorporating alkaline earth metal silicates in curable organopolysiloxane compositions. Spinel compositions, such as iron-manganese spinels are described in U.S. Pat. Nos. 4,604,375 to Soled et. al. and 4,618,597 to Fiato. These spinel compositions are used as catalysts in the conversion of CO/H.sub.2 to alpha-olefins.
Therefore, it is an object of the present invention to provide curable organopolysiloxane compositions having reduced compression set. Another object of the present invention is to provide silicone rubber having reduced compression set. Still another object of the present invention is to provide a process for preparing organopolysiloxane compositions which when cured have reduced compression set. A further object of the present invention is to provide a process for preparing silicone rubber having reduced compression set.